ISSN:
1432-0428
Keywords:
Juvenile type diabetes
;
muscular exercise
;
blood glucose
;
ketosis
;
free fatty acids
;
amino acids
;
insulin
;
glucagon
;
growth hormone
;
cortisol
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Metabolic and hormonal effects of muscular exercise were studied in juvenile-type diabetics in relation to the prevailing degree of metabolic control and compared with those in healthy control subjects. Two groups of diabetic patients, one in moderate metabolic control and one in ketosis due to insulin withdrawal, were subjected to a 3 hour bicycle ergometer test of comparable, mild work intensity. In both groups of diabetics the exercise-induced rise in blood lactate was similar, but was significantly higher than in control subjects. Blood alanine levels showed a transient, significant rise in both diabetic groups, but not in controls. Blood concentrations of branch-chained amino acids remained unchanged. In the moderately controlled diabetics, exercise induced a marked fall of blood glucose and increases in blood levels of free fatty acids (FFA), ketone bodies and glucagon, which were comparable to the exercise effects in normal controls. In ketotic diabetics, however, exercise led to an additional rise in blood glucose concentration and to increases in ketone body, glucagon and cortisol levels. Significant correlations were found between the exercise effect on blood glucose and initial blood levels of glucose, FFA, ketone bodies and branch chained amino acids: pre-exercise values of above 325 mg/dl glucose, 1173 μmol/l FFA, 2.13 mmol/l ketone bodies and 0.74 mmol/l branch chained amino acids led to increased blood glucose levels on exercise, whereas below these limits glucose fell during the exercise test. These findings seem to be, at least in part, explained by the hypothesis of a permissive effect of insulin during stimulation of muscle glucose uptake by exercise. The increased circulating levels of glucagon and cortisol during exercise in ketotic diabetics might represent additional hyperglycaemic and, probably more important, lipolytic and ketogenic stimuli. The results suggest that in moderately controlled, non-ketotic diabetics blood glucose falls during exercise; in ketotic, relatively insulin deficient patients, muscular activity has adverse metabolic and hormonal effects: a further increase in blood glucose, plasma glucagon and cortisol and a rapid aggravation of ketosis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01223279
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